MF just a couple of observations, the dinosaurs as you describe changed the way that lawns were cut in this country, and while they were dangerous they did an amazing job and because of their shape and style they became a collectors dream. The next 10 years of full cranks lost this appeal although still a fantastic motor. The appeal to me was lost due to the lack of catchers still around. If catchers were still around I would keep putting them back into service because people are becoming aware of the fact most of the new stuff is rubbish. These days I keep the full cranks for slashers and utilitys , people still want those. Then we have the PT's that will never be collectible but are probably the best workhorse mower ever made with the exception of the bad points BB often mentions, metal base with badly designed handle mounts and a carby that can be problematic but this can be modified into a very reliable unit